42 GERMINAL SELECTION. 



our common whales, are rendered useless. Panmixia 

 steps in, i. e., selection ceases to influence these organs. 

 Individuals with large and individuals with small hind 

 legs are equally favored in the struggle for existence. 

 From this fact alone would result a degradation of 

 the organ, but of course it would not be very marked 

 in extent, seeing that the minus variations which occur 

 are no longer removed. According to our assumption, 

 however, such minus variations repose on the weaker 

 determinants of the germ, that is, on such as absorb 

 nutriment less powerfully than the rest. And since 

 every determ inajnt battles stoutly with its neighbors 

 for food, that is, takes to itself as much of it as it 

 can, consonantly with its power of assimilation and 

 proportionately to the nutrient supply, therefore the 

 unimpoverished neighbors of this minus determinant 

 will deprive it of its nutriment more rapidly than was 

 the case with its more robust ancestors; hence, it will 

 be unable to obtain the full quantum of food corre- 

 sponding even to its weakened capacity of assimilation, 

 and the result will be that its ancestors will be weak- 

 ened still more. Inasmuch, now, as no weeding out of 

 the weaker determinants of the hind leg by personal 

 selection takes place on our hypothesis, inevitably the 

 average strength of this determinant must slowly but 

 constantly diminish, that is, the leg must grow smaller 

 and smaller until finally it disappears altogether. The 

 determinants^ of the useless organ are constantly at 



1 1 speak here of determinants, not of groups of determi- 

 nants, which is the more correct expression, merely for the 

 sake of brevity. It is a matter of course that a whole 

 extremity, such as we have here chosen, cannot be repre- 

 sented in the germ by a single determinant only, but requires 

 a large group of determinants. 



